Some researchers suggest depression is underreported in men. One recent study found that primary care doctors and internists were 36 percent less likely to find mental health problems in men than in women. This may be so partly because men are more likely to shy away from talking about their symptoms, and doctors are less likely bring up emotional topics with men.

There are other, more complex reasons for women's greater vulnerability to depression. For example, work can be a source of chronic stress. On the other hand, it's important to note that a demanding job doesn't automatically trigger such stress. A recent, four-year study of more than 21,000 female American nurses that appeared in the British Medical Journal concluded that the factors most detrimental to a woman's mental and physical health were a combination of insufficient workplace social support and a feeling of inadequate control over a demanding job.

In addition, poverty and physical and sexual abuse are risk factors for depression, and each of these social ills touches women disproportionately. In the United States, three-quarters of those below the poverty line are women and children. A report addressing violence against women worldwide, which appeared in the international journal Population Reports, estimated that one woman in three will suffer beatings, sexual coercion, or other forms of abuse in her lifetime.

Another recent study of roughly 1,100 adults in the Journal of Personality and Social Psychology found that women were more likely than men to experience chronic stress and feel that their lives were out of their control. In part, this may reflect the strains of social responsibilities that are often yoked to women, such as housework, child-care, and caring for older relatives -- which comprise the so-called "second shift" for women who work outside the home. But the researchers also found that women were more likely to ruminate than men were. That is, they would frequently talk and brood about unhappy or stressful aspects of their lives without problem-solving or taking action to effect changes. While discussing problems can be helpful when it leads to their resolution or to the development of a plan of action, simply brooding over a problem seems to plunge spirits further.

Marriage and children, while a haven for some women, ratchet up the stress level for others. Studies have found that, compared to their single counterparts or to married men, married women are less likely to feel satisfied. Simply being a mother of young children increases your risk for depression.

Conversely, infertility, which affects one in 10 couples, can also be a source of depression for women. Its treatment often calls for hormonal manipulation -- including drugs that deliver whopping doses of sex hormones known to affect mood -- and sometimes involves a string of invasive medical procedures. Hopes may be raised one moment, dashed the next. The sadness of wanting a child but being unable to bear one can be profound, and reminders are rife, as friends and acquaintances sail into parenthood.

From the Harvard Health Publications Special Health Report, Depression Report. Copyright 2002 by President and Fellows of Harvard College. All rights reserved.